/// <summary> /// Determines if the given value represents a valid state of this property. /// </summary> /// <param name="value">The state that should be used.</param> /// <returns>True if the state is valid, otherwise false.</returns> protected override Boolean IsValid(CSSValue value) { var mode = value.ToBorderSlice(); if (mode != null) { _top = _left = _bottom = _right = mode; } else if (value is CSSValueList) { return(Evaluate((CSSValueList)value)); } else { return(false); } return(true); }